GeneveOS Device Operation
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Accessing devices (floppy disk, hard disk, serial connector, printer) is possible in GeneveOS via XOP calls.
User-task XOPs
User-task XOPs are available for use in application programs. Here is a typical example:
PABADD EQU >F180 FILE DATA 8 ... LI R0,PABADD XOP @FILE,0 MOVB @PABADD+2,R0 JNE SF7 ...
Similar as with the TI-99/4A device service routine concept (DSR), a Peripheral Access Block (PAB) must be set up prior to invoking the XOP.
Available memory pages
Opcode: 0
Input | Output | |
---|---|---|
R0 | Opcode (0000) | Error code (always 0) |
R1 | Number of free pages | |
R2 | Number of fast free pages | |
R3 | Total number of pages in system |
This function is used to query the free space in the system. No changes are applied. The total number of pages are the maximum number of allocatable pages.